Lauric fractionated and hydrogenated hard butters have been used for some time in replacing cocoa butter in confectionery coatings. They enjoy an advantage over domestic hard butters in that their shorter chain length and high degree of saturation enable them to have good eating quality and good oxidative stability or keeping time. They normally are used as substitute or replacement fats for cocoa butter, since they have only very small tolerance, e.g., 5% maximum, for diluent fats such as cocoa butter, butterfat and chocolate liquor. Higher amounts of diluent fats are apt to induce bloom.
Normally, these hard butters have to be tempered when they are used in confectionery coatings. Tempering is a thermal process that stabilizes the crystal structure of the hard butter in the coatings, thus providing the coatings with better shelf life. It is known to add other lipoidal substances, e.g., lipoidal emulsifiers, to the hard butters to stabilize the crystal structure, alleviating the need for tempering. These emulsifiers, however, also affect the physical properties and organoleptic characteristics of the coating when they are used, and some of the properties are improved while others are degraded.
Usually, two, three, or more of the lipoidal emulsifiers may be used together, in the hope of providing a synergistic effect designed to improve most of the properties of the coating while not degrading the rest of the properties.
By way of example U.S. Pat. No. 2,586,615 teaches the value of sorbitan monostearate and polyoxyethylene sorbitan monostearate (polysorbate 60) as a bloom inhibitor in chocolate compositions containing cacao fat with or without other vegetable fats. A similar combination was found to act as an "inhibitor against dulling", as disclosed in U.S. Pat. No. 2,671,027. Prior U.S. Pat. No. 2,999,023 refers to the value of sugar esters for gloss enhancing. In the publication "Food Engineering", of May, 1967, pages 79-82, polyglycerol esters are mentioned as being useful for confectionery coatings and chocolate, to maintain gloss properties. They are also said to minimize tempering and handling problems. Specific polyglycerol esters mentioned were triglycerol monooleate and decaglycerol trishortening. British Pat. No. 1,297,579 teaches the use of polyglyerol esters in chocolate compositions to obtain aeration of such compositions. Tri- and tetraglycerol esters were mentioned as being preferred.
Glyceryl-lacto esters of fatty acids, also referred to as lactylated mono- diglycerides, have been known for some time. They are the reaction product of lactic acid and mono- diglyceride carried out in the presence of heat. Their manufacture is described in U.S. Pat. No. 2,957,932, assigned to assignees of the present application. The disclosure of this patent is incorporated by reference herein. Manufacture of these compounds is also disclosed in Barsky U.S. Pat. No. 2,509,414.
Mostly, the glyceryl-lacto esters have been used as emulsifiers for cake mixes. This is described in British Pat. No. 980,131, dated Jan. 13, 1965, and, more recently, in Morgan et al U.S. Pat. No. 4,242,366.
In Babayan et al U.S. Pat. No. 3,051,577, it is disclosed that glyceryl-lacto fatty acid esters can be added to either a hard butter or cocoa butter to give enhanced initial and permanent gloss. It is indicated in the patent that glyceryl-lacto oleate gave the best gloss results. In a coconut type fat having C.sub.16 and C.sub.18 type fats, the lactopalmitate was said to be best.
In Buddemeyer et al U.S. Pat. No. 3,752,770, glyceryl-lacto esters were blended with another emulsifier such as an ethoxylated monoglyceride, polysorbate 60 or propylene glycol monostearate, and found to be especially useful in baked products. Other applications mentioned include vegetable dairy products such as puddings, confections, ice cream and ice milk. No mention is made of a high sugar confection coating or of a desire to achieve high gloss and gloss retention.
In corresponding application Serial Number 439,336, assigned to assignees of the present application, it was found that a unique blend of polyglycerol ester emulsifiers gave improved gloss and gloss retention in lauric and non-lauric hard butters. By way of example, one such blend was a combination of octaglycerol monooleate and octaglycerol monostearate.